The present invention relates to a vehicle seat with a backrest that can be pivoted relative to a seat portion about a lateral axis. The backrest includes two longitudinal beams defining its lateral sides and a thin plate which is rigidly connected to the two longitudinal beams along its two lateral edge areas.
In known seats of this type, the torsional rigidity of the backrest depends largely on the stiffness of the longitudinal beams because of the limited thickness of the plate forming the center portion of the upholstery support. An increase in the torsional rigidity therefore requires a reinforcement of the longitudinal beams which, however, is undesirable because of the increased weight.